Well, I'm sure this is not your first time reading something as cringe as well as cliche and boring novel.
Something about dungeons, towers, dimensions and portals coming out of nowhere spawning monsters and demi-humans at the same time.
And MC getting a weird system and got op(overpowered) as little time passes. Girls would then fight or witness MC's prowess then fall for him then sooner or later... "boom"!! MC's gets his HAREM easily.
Well anyways,this is just my introductory massage for anyone who might be reading this.